At this late point I am not sure if I have posted on this thread before or not. If so please forgive me, if not, here goes. I happened to have been probably one of the few people who has had both R4's and R1's on the same tractor, a JD 3720. My two cents: The R1 tires get better overall traction. The difference is not huge but certainly notable. The R1's are very narrow on the JD machine. The sidewalls on mine notably flexed when the bucket was full of heavy rock or mulch, a problem not seen with the R4's. The R1's do not hold as much ballast, only 24 gallons per tire v. 35 with the R4's. This equates to a 80-120 pound difference depending on ballast type between the two. In short, you will have to add wheel weights if using heavy front end implements with a JD 3000 series or smaller tractor. The R1's ride surprisingly smoothly on pavement, in my opinion MORE smoothly than R4 tires, perhaps due to their larger circumference. The other little nice thing is with the additional clearance the three point hitch can be fully lifted without impacting the ROPS if you have it folded for some reason, but DON'T fold it!! The R1's are not nearly as stable as the R4's at the conventional wheel postion, shallow dish wheel out and bracketed on the outside (ie the second position). I nearly rolled my tractor twice due to a front wheel burying in mud on a steep hill and the back end kicking over. Perhaps this would be made better if one has the wheels set maximally wide, but that to me looks ridiculous and inhibits getting into tighter places. But, it is safer. Bear in mind most R1 tires are quite a bit taller than their R4 counterparts and will make most tractors ride higher and thusly be a bit less stable. For all these reasons I went back with the R4's but I really enjoyed the additional box blade pull and drawbar pull given by the R1's. For me though, R4's were the better choice and I have been happy with them.
John M
